Contrasting changes in the abundance and diversity of North American bird assemblages from 1971 to 2010.

摘要: Although it is generally recognized that global biodiversity declining, few studies have examined long-term changes in multiple dimensions simultaneously. In this study, we quantified and compared temporal the abundance, taxonomic diversity, functional phylogenetic diversity of bird assemblages, using roadside monitoring data North American Breeding Bird Survey from 1971 to 2010. We calculated 12 abundance metrics based on 5-year average abundances 519 species for each 768 routes. did all together as well four subgroups breeding habitat affinity (grassland, woodland, wetland, shrubland breeders). The majority increased or remained constant over study period, whereas overall birds showed a pronounced decrease, primarily driven by declines most abundant species. These results highlight how stable even increasing taxonomic, functional, may occur parallel with substantial losses individuals. further found patterns change differed among subgroups, both woodland decreasing grassland breeders. contrasting between groups underscore relevance multifaceted approach measuring change. Our findings stress importance individuals addition thus confirming population an essential variable.